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我有个问题。我需要将 base64 字符串转换为 JSON 字符串并将其传递给服务器。例如我有一个 base64 字符串/9j/4AAQSkZJRgABAQAAAQABAAD/4QBYRXhpZgAATU0AKgAAAAgAAgESAAMAAAABAAEAAIdpAAQAAAABAAAAJgAAAAAAA6ABAAMAAAABAAEAAKACAAQAAAABAAAACqADAAQAAAABAAAACgAAAAD/2wBDAAEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQH/Z

我需要将其转换为 JSON 格式。我执行以下操作：

+(NSData *)prepareForUploading:(NSString *)base64Str
{
    NSDictionary *dict=[NSDictionary dictionaryWithObjects:[NSArray arrayWithObjects:base64str, nil] forKeys:[NSArray arrayWithObjects:@"picture", nil]];

    NSData *preparedData=[NSJSONSerialization dataWithJSONObject:dict options:NSJSONWritingPrettyPrinted error:nil];    
    return preparedData;
};

这里我是怎么做的NSURLRequest

-(NSString *)uploadPict:(NSString *)pict
{
    NSLog(@"Server: upload: called");
    NSData *prepPictData=[[self class] prepareForUploading:pict];
    NSString *preparedBase64StrInJSON=[[NSString alloc] initWithData:prepPictData encoding:NSUTF8StringEncoding];

    //here I'm adding access token to request
    NSString *post = [NSString stringWithFormat:@"accessToken=%@&object=%@", self.key, preparedBase64StrInJSON];
    NSData *postData = [post dataUsingEncoding:NSUTF8StringEncoding allowLossyConversion:YES];
    NSString *postLength = [NSString stringWithFormat:@"%d", [postData length]];

    NSMutableURLRequest *request = [[NSMutableURLRequest alloc] init];
    [request setURL:[NSURL URLWithString:[NSString stringWithFormat:@"%@upload.aspx", serverAPIPath]]];
    [request setHTTPMethod:@"POST"];
    [request setValue:@"postLength" forHTTPHeaderField:@"Content-Length"];
    [request setValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"Content-Type"];
    [request setHTTPBody:postData];    

    NSURLResponse *response;
    NSError *error;
    NSData *urlData=[NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error];
    //....
}

但是我从服务器收到“Base-64 字符数组的长度无效”。怎么了？如果我将令牌和 JSON 粘贴到http://hurl.it/并使用它发出请求 - 一切正常。

我认为问题在于/base64 字符串中的符号以及 JSON 中的 / 符号。也许是这样的[postData length]：如果我从 JSON 字符串中删除\/字符： 9j4AAQSkZJRgABAQAAAQABAAD4QBYRXhpZgAATU0AKgAAAAgAAgESAAMAAAABAAEAAIdpAAQAAAABAAAAJgAAAAAAA6ABAAMAAAABAAEAAKACAAQAAAABAAAACqADAAQAAAABAAAACgAAAAD2wBDAAEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQHZ请求将正常执行，但这个 base64 编码的字符串不一样。

请帮我解决这个问题

4

1 回答 1

5

jString 是您的 base64 字符串，首先使用以下行

[self encodeString:jString];

然后调用使用以下。

NSString *URL = [NSString stringWithFormat:@"forms.asmx/CreateUpdate?"];

URL=[NSString stringWithFormat:@"%@%@", USERS_API_ROOT_URL, URL];
NSString *post = [NSString stringWithFormat:@"apiKey=A0B1I2L3A4L5-A1D3-4F30-5AB2-C8DEE266&strPost=%@",jString];

unsigned long long postLength = [post length];
NSString *contentLength = [NSString stringWithFormat:@"%llu",postLength];

NSData *postData = [post dataUsingEncoding:NSUTF8StringEncoding allowLossyConversion:YES];

NSMutableURLRequest *request = [[NSMutableURLRequest alloc] init] ;
[request setURL:[NSURL URLWithString:URL]];
[request setHTTPMethod:@"POST"];
[request setValue:contentLength forHTTPHeaderField:@"Content-Length"];
[request setValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"Content-Type"];
[request setHTTPBody:postData ];

(void)[[NSURLConnection alloc] initWithRequest:request  delegate:self];


-(NSString *)encodeString:(NSString *)string
{
    NSString *newString = (__bridge_transfer NSString*)CFURLCreateStringByAddingPercentEscapes(kCFAllocatorDefault, (CFStringRef)string, NULL,CFSTR(":/?#[]@!$ &'()*+,;=\"<>%{}|\\^~`"), CFStringConvertNSStringEncodingToEncoding(NSUTF8StringEncoding));
    return newString;
}

希望它会奏效。

于 2013-01-30T13:22:37.327 回答